Disconnect couplings are frequently used in a variety of fluid transfer systems, including both high pressure and low pressure systems and gas and liquid systems for quickly and relatively conveniently connecting and disconnecting the fluid-flow supply and discharge lines. Many of these couplings are equipped with quick-disconnect or quick-action features and automatic means to shut off the flow of liquid when the mating parts of the coupling are disconnected.
Quick-action couplings typically comprise two primary components, or members: a generally cylindrical socket having an axial fluid-flow pathway and configured to be attached to one line, and a generally cylindrical plug also having an axial fluid-flow pathway and configured to be attached to another line. The plug is inserted into the socket to join the two lines and to create a single fluid-flow pathway between the lines. Generally speaking, the socket has a plurality of evenly spaced locking balls contained in apertures arranged in a circle around the receiving end of the socket. A spring biased detent sleeve circumscribing the socket holds the locking balls radially inwardly. To insert the plug into the socket, the operator first uses one hand to pull the detent sleeve longitudinally away from the plug receiving end of the socket so that the balls are released. Using the other hand, the operator inserts the plug into the socket. The plug has an annular groove, or race, for receiving the locking balls. The operator then releases the detent sleeve, which holds the balls in the annular groove and the plug, and secures the plug in the socket. The operator removes the plug from the socket in an analogous fashion. Additionally, push-to-connect, or automatic, couplings exist that do not require the operator to pull and release a detent sleeve. In operation, the detent sleeve of an automatic coupling is configured to retract upon inserting a plug into a socket.
Valves are typically included in the fluid flow passageway to urge the plug out of coaxial coupled relation and stop the fluid flow when the plug and socket are released from coaxial coupled relation. Conventional valves typically are fixedly mounted on a valve member. The valve member is mounted in a valve body, also called a spider, which is located within a valve cavity along a flow pathway. The valve body acts to axially locate the valve member and valve within the coupling member. A coil spring, or valve spring, is generally mounted over the valve member and urges on one end against the valve body and on the other end against the valve member to urge the valve into contact with a seat within the coupling member to shut off flow. When the coupling members are joined, the valve is typically urged against the bias of the spring and away from the seat to provide a fluid-flow pathway around the valve.
Assembly of the valve into the socket is often difficult given the number of components needed to be positioned precisely and accurately in a relatively small space. Varying operating conditions for the valves necessitate different valve designs often requiring sockets configured for each different valve design. As a result, the valves add complexity to socket design and require a considerable amount of assembly, thereby increasing the production costs of the socket. Thus, it is desirable to have a variety of valve components that are easy to assemble and that can be incorporated into a single socket design.
It is also desirable to have a valve design that can form a seal quickly after the plug has been removed from the socket and a design that reduces the possibility of having the valve become misaligned or wedged in the valve member thereby preventing the valve from closing. Further, certain fluid transfer systems utilize fluids stored and transferred through lines under high pressures requiring a valve design capable of maintaining a seal and reducing the possibility of a valve being dislodged from a valve cavity of the socket. Such features are also desirable to prevent leakage into the surrounding environment.
Accordingly, there is a need for an improved valve design and assembly process to reduce the cost of assembling valves in sockets of fluid transfer systems and to provide for a valve that resists being dislodged from the socket due to high pressure from the fluid and to quickly and consistently form a reliable seal.